810491985097 has 2 divisors, whose sum is σ = 810491985098. Its totient is φ = 810491985096.

The previous prime is 810491985073. The next prime is 810491985101. The reversal of 810491985097 is 790589194018.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 446636919481 + 363855065616 = 668309^2 + 603204^2 .

It is a cyclic number.

It is not a de Polignac number, because 810491985097 - 2³⁹ = 260736171209 is a prime.

It is not a weakly prime, because it can be changed into another prime (810491925097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 405245992548 + 405245992549.

It is an arithmetic number, because the mean of its divisors is an integer number (405245992549).

Almost surely, 2^810491985097 is an apocalyptic number.

It is an amenable number.

810491985097 is a deficient number, since it is larger than the sum of its proper divisors (1).

810491985097 is an equidigital number, since it uses as much as digits as its factorization.

810491985097 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6531840, while the sum is 61.

The spelling of 810491985097 in words is "eight hundred ten billion, four hundred ninety-one million, nine hundred eighty-five thousand, ninety-seven".